Container with sensor

ABSTRACT

A sealed container is provided with a sensor capable of monitoring the physical and/or chemical condition of materials stored in the container. The sensor may or may not have its own power source. In the embodiment where the sensor does not have a power source, a communicator induces a signal in the sensor and receives a return signal with the desired data. The container may be a metal or a nonmetal.

TECHNICAL FIELD

The present invention relates to a method and apparatus for monitoringstored chemicals.

BACKGROUND OF THE INVENTION

It is sometimes necessary to store chemical compositions that aresensitive to heat, moisture, and pressure, as well as chemicals that arevolatile or subject to degradation, for long periods of time. Thephysical or chemical condition of the chemicals can be monitored bytesting samples of the chemical, but such sampling is time consuming,wastes materials, and is sometimes risky.

Nevertheless, for quality assurance, safety, and other reasons, it isimportant to know when chemicals, such as fertilizers, rocket fuels, andexplosives, are or have been overheated, decomposed, contain too muchmoisture, or are subjected to other undesirable conditions. In someinstances, it is not practical to break open the containers and samplethe chemicals to determine their condition.

Accordingly, it is a goal of this invention to create a method andapparatus for quickly and accurately determining the condition of achemical composition while the chemical composition is in a sealedcontainer.

Other objects of the invention will be apparent from the followingdescription and claims.

DESCRIPTION OF THE PRIOR ART

Systems for monitoring vehicle tire pressure and the like have beenproposed wherein a transmitter and a receiver are mounted on a vehiclebody, and magnetically coupled inductor and enhancer circuits arecarried on the vehicle wheel to provide monitoring a vehicle tirepressure, as described by Allen in U.S. Pat. No. 4,588,978. Otherdevices to monitor tire pressure have been proposed by Galasko et al.,in U.S. Pat. No. 4,578,992, who teach a coil mounted in a tire whichforms, with a capacitor, a passive oscillatory circuit. The circuit isenergized by pulses supplied via a coil positioned outside the tire andsecured to the vehicle, and the frequency in the passive oscillatorycircuit is varied with tire pressure due to changes caused to thecapacitance value of the capacitor. The frequency in the circuit issensed by a coil positioned outside the tire and secured to the vehicle.

Milheiser, in U.S. Pat. No. 4,730,188, teaches the use of a passiveintegrated transponder which is attached to or imbedded in an item to beidentified, and is excited by an inductive coupling from aninterrogator.

Fiorletta, in U.S. Pat. No. 5,289,160, teaches a wireless tire pressuremonitoring system European Patent Application (EPA) 0312168 teaches amethod and apparatus for electronically identifying articles movingalong a surface, especially where the surface and/or articles compriseconductive material. The article is fitted with electronic responders,and the surface is provided with electrodes of a transceiver device.When the responders are located opposite the electrodes, a signal issent.

EPA 0812,752 relates to an electromagnetic transmission and detectionsystem comprising a transmission coil for producing a high intensitymagnetic field, and first and second receiving coils for receiving a lowintensity magnetic field from an inductively powered transponder. Aferrite rod is used to resonate the same operating frequency so that theenergy transferred between the transmitter and the transponder ismaximized.

PCT application WO91/07736 teaches a high temperature monitor that canbe used near conductive objects that produces unwanted reflectedimpedance, and can be used to monitor the temperature within soup cans,and the like.

PCT application WO04/27117 teaches a security system which uses acontainer that has sensors for predetermined physical stimuli, forexample a pressure sensor. The container contains a transponder fortransmitting data from the sensor without opening the container.

DISCLOSURE OF INVENTION

A method of monitoring physical parameters of a composition enclosed ina container comprises the steps of (a) embedding a id-tag/sensor(transponder) in a composition wherein the sensor is capable ofmeasuring physical parameters of the composition, (b) enclosing thecomposition in a container, (c) winding an antenna around the containerin the proximity of the sensor, (d) bringing a communication means intoproximity to the antenna, and (e) activating the sensor through theantenna using the communication means, and receiving and recording aresponse from the sensor using the communication means.

A ferrite core may be associated with the sensor for amplifying signalsto and from the sensor.

Further, the physical parameters measured may be selected from the groupcomprising-pressure data, temperature data, moisture content data,chemical data and mixtures thereof.

The sensor may be enclosed in a loop of wire, wherein the sensor iselectrically coupled with the wire to form a coupled sensor, a secondwire may be placed adjacent to the is coupled sensor, and an antenna maybe placed adjacent to the second wire.

In an alternative embodiment, the method may comprise the steps of (a)embedding an E-field sensor in a chemical composition, the E-fieldsensor being capable of measuring physical parmeters of said chemicalcomposition, (b) enclosing the composition in a container, (c) placingan E-field antenna at opposed sides of the container, (d) creating anE-field in the antenna using an E-field driver to induce a signal in andreceive a signal from the sensor, (d) bringing an E-field reader intoproximity to the antenna, and (e) receiving and recording a responsefrom the sensor.

In the methods, the receiving antenna may be placed inside or outsidethe container, it being important only that the receiving antenna be inclose proximity to the transponder.

Also provided is a container for containing a chemical composition, thecontainer comprising (a) impenetrable materials completely enclosing aninterior space and having an inside and an outside, (b) an id-tag/sensordisposed inside the container, the id-tag/sensor being capable ofretaining identification information and measuring physical or chemicalparameters of the interior space, and an antenna associated with thesensor.

The antenna may comprise at least two loops of wire, a first wire beingdisposed in the proximity of the impenetrable material of the containerand the sensor, and a second wire being disposed around the container.The first wire may be inside or outside the container. The first wire isused as a receiving antenna and the second wire is used as atransmitting antenna for the id-tag/sensor, and the id-tag/sensor isactivated by communication means associated with the transmittingantenna.

The sensor may be a ferrite core pressure and temperature sensor havingid information associated therewith, and the impenetrable material ofthe container may be a metal or a nonmetal.

In an alternative embodiment, the sensor may be in proximity to andcoupled to a loop of wire disposed in the proximity of the impenetrablematerial of the container, and the loop of wire may be inductivelyassociated with an antenna outside the container.

In another alternative embodiment of the container, the id-tag/sensormay comprise a chip sandwiched between an upper electrode and a groundelectrode wherein the sensor is activated by at least two E-field platesat opposed sides of the id-tag/sensor. A first E-field plate maycomprise a metal core in the interior of the container, and a secondE-field plate may comprise the impenetrable material of the container.Alternatively, a first E-field plate may comprise a flat metal upperplate disposed on -a first side of the container, and a second E-fieldplate may comprise a flat metal ground plate disposed on a second,opposed side of the container.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 illustrates antenna wire surrounding a container which has anid-tag/sensor inside.

FIG. 1a illustrates an alternative configuration of FIG. 1 wherein atleast one antenna wire is inside the container.

FIG. 2 illustrates a container having a sensor inductively coupled witha loop of wire inside the container which is further coupled with anexterior antenna.

FIG. 2a illustrates a container having a sensor inductively coupled witha loop of wire outside the container which is further coupled with anexterior antenna.

FIGS. 3 and 3a illustrate, respectively, a perspective view and a sideview of a chip sandwiched between an upper electrode and a groundelectrode.

FIG. 4 illustrates a container wherein a sensor is enclosed inside, andplates capable of creating an E-field are disposed at sides of thecontainer.

FIG. 5 illustrates a container wherein a metal core in the container andthe container material are capable of creating an E-field.

DETAILED DESCRIPTION OF THE INVENTION

In the art relating to the gathering of information from an animate ordynamic objects, the trend has been toward implanting a device which iscapable of transmitting information and is responsive to an outsidepower source. This is accomplished by including a coil (which is capableof carrying an induced electrical current) of some sort in the implanteddevice. An electrical current can be induced in the coil by a magneticfield produced by an interrogator as the lines of flux from the magneticfield cut across the coil. The current produced in the coil, in turn,produces a magnetic field which can be read by the interrogator. Thecurrent in the coil, and the signal read by the interrogator, can bealtered by electrical devices used to provide tire data, such astemperature and pressure sensors, and these differences in the signalcan be read and interpreted by the interrogator.

A transponder used in the invention may be similar to that illustratedin U.S. Pat. No. 5,181,975 (applcation Ser. No. 676153) and U.S. Pat.No. 5,218,861 (application Ser. No. 676121), assigned to The GoodyearTire and Rubber Company, and commonly assigned application. Ser. Nos.PCT/97/22570, PCT/97/22571, and PCT/97/22463, and may provideidentification data, and may be used to monitor pressure, thetemperature, the chemical composition of the container and the like.

The transponder or signal generator means may comprise a chip andconducting wires which are used to receive a signal from a communicatorand to transmit data in response to the communicator signal.

An antenna may be provided, in the illustrated embodiment, in one ormore turns of conductor wire. Although a sufficient signal may beobtained with one turn of wire, the signal is boosted as additionalturns are added since the amount of current developed is dependent onthe number of lines of magnetic flux encountered by the antenna inaccordance with the ampere law.

Three different wires, for example, can be used to obtain three turns ofantenna wire.

With reference now to FIG. 1, a container 10 of the invention isillustrated as having a cylindrical shape. Although other shapes arepossible for containers of the invention, cylindrical shape may berepresentative of rockets, artillery shells, and drums of fertilzer,which are used as examples of containers which are embodied by thepresent invention.

In FIG. 1, at least one antenna wire (two antenna wires 14 and 16 areillustrated) are exterior (outside) of the material 18 comprising thecontainer. A transponder 12 comprising a ferrite core passive sensor(PST) is located in the interior of the container (inside), in closephysical contact with the material 17 stored in the container, i.e.,within the substance that is monitored.

The material 18 of the container is impenetrable, i.e., it is capable ofholding or containing the material for which it is designed for asubstantially indefinite period of time under normal conditions. Bynormal conditions it is meant that the container is not subjected tosignificant outside stimuli. Non-limiting examples of container materialmay include cardboard, fiberglass, paper, metal and glass.

With reference now to FIG. 1a, in an alternative embodiment, at leastone antenna wire 14 a is outside container 10 and at least one antennawire 16 a is inside container 10.

In FIGS. 1 and 1a, the at least one antenna wire 14,14 a is used as atransmitting antenna for transponder 12 and the at least one antennawire 16,16 a is used as a receiving antenna for transponder 12.

As illustrated, receiving antenna wire 16,16 a must be in closeproximity to transponder 12, but transmitting antenna wire 14,14 a maybe remote from transponder 12. For example, receiving antenna 16 may bedisposed in close proximity to the skin of a rocket, either inside oroutside the skin of the rocket, and the transmitting antenna 14,14 a maybe disposed around the rocket's container or silo. When a communicator,such as an interrogator, sets up a signal in the transmitting antenna,the signal is boosted and then picked up by the receiving antenna,through which the transponder is activated.

In some embodiments of the invention, the transponder may beconductively connected to the antenna wire in the manner disclosed inthe copending PCT applications mentioned above. For most applications,however, it is preferred that the transponder be free of the antennawire and be designed to be activated by an inductive signal through theantenna.

Although an interrogator, as described in the patents and applicationscited herein, may be used to induce a signal in the transponder, formany applications it will be more convenient to conductively connect acommunicator (not shown) to the antenna through leads. The communicatorcan then be used to transfer an electrical current directly to theantenna, as opposed to inducing such a current when an interrogator isused. The signals may be generated in the same manner as described foran interrogator.

The communicator may be powered by a battery or an alternating current(AC) or direct current (DC) generator. Those skilled in the art willknow how to generate, receive and process signals generated by any powersource.

Since metals dissipate some signals, for best results, containermaterial 18 in the illustrated embodiments of FIGS. 1 and 1a should be anonmetal.

In an alternative embodiment of the invention, as illustrated in FIGS. 2and 2a, the transponder 26, with the desired sensors, may be inductivelycoupled to an antenna wire 22,22 a which may be either inside or outsidethe container 10 a. In such an embodiment, the transmitting antenna 24is, similar to the embodiment shown in FIGS. 1 and 1a, remote fromtransponder 26.

Although antenna 24 is illustrated as a woven wire grid, those skilledin the art will recognize that antenna 24 may be in any suitable formfor inducing a signal in receiving antenna 22,22 a and picking up areturn signal therefrom.

As was the case in the embodiment of FIGS. 1 and 1a, for best resultsthe material 18 a of container 10 a will preferably be a nonmetal.

In a further alternative embodiment, data signals may be provided by anE-field generator.

When an E-field application is used, a transponder 36 is sandwichedbetween an upper electrode 15 and a ground electrode 30, as illustratedin FIGS. 3 and 3a, and capacitance between the upper electrode 15 andground electrode 30 activates a signal from transponder 36.

As further illustrated in FIG. 4, an E-field is induced in upper plate15 by a charge created in charge plate 46 by E-field driver 48.Conductor 45 connects E-field driver 48 with charge plate 46 and groundplate 44.

As in the earlier embodiments, for best results, it is preferred thatcontainer material 18 b of container 10 b be a nonmetal.

With reference now to FIG. 5, in an alternative use of an E-fielddriver, a metal core 54 may be provided in the center of container 18 cto act as a charge plate when connected to E-field driver 48 throughconductor 55. In such an embodiment, the material 18 c of the containermay be a metal, and the material 18 c may act as the ground plate forthe E-field driver when connected to E-field driver 48 through conductor55.

One of the primary uses for the apparatus of the invention is to providedata on the history as well as the present condition of the chemicalcomposition. It is important to know if the chemical composition hasencountered excessively high temperatures. The chip in transponder 12,36, can be provided with means to collect pressure and temperature dataand to receive information on the current condition of the chemicalcomposition, to be retained along with identification data.

In the illustrated embodiment, transponder 12,36 may be activated by acommunicator that transmits at a specific radio frequency and the chipresponds by stepping down the radio signal to transmit one-half theradio frequency in a return signal. The radio frequency is heterodynedagainst the return signal frequency producing a difference side band toreinforce the return signal response.

In the illustrated embodiment, the temperature reading is obtained bycounting and entering into memory of the communicator the number ofcycles output from an oscillator, the frequency of which is proportionalto temperature. The temperature can be read by converting a voltagesignal to a digital display, where there is a band gap voltage shiftwith a change in temperature.

Alternatively, a temperature can be read by a switch which is operatedby the linear thermal expansion of the materials from which it isconstructed. The switch is designed to change signals, i.e. from thebinary 0 to 1 for example, when the maximum designated temperature isexceeded. The switch cannot be reset, and a change in the binary signalof the switch indicates that the container has been thermallycompromised.

In the illustrated embodiment, the pressure sensor provides real timeinformation, that is the pressure in the container at the time of thereading.

In the illustrated embodiment the pressure sensor provides a capacitancemeasurement which is directly related to the pressure. In the pressuresensor, a highly doped silicon electrode having a thin flexiblediaphragm micromachined (etched) into its center, is placed over anelectrically conductive substrate, and the distance of separation of theflexible diaphragm from the substrate controls the resultingcapacitance. Silicon dioxide is used as an electrical insulator,preventing shorting between the substrate and the electrode. The surfacearea of the oxide coating and its distance of separation from thesubstrate controls the capacitance reading. Accordingly, as the pressureincreases, the distance of separation between the silicon and substrateelectrodes decreases, and the capacitance changes, and a measurement ofthe capacitance can be digitally converted to a pressure reading inpounds per square inch, or other dimensions as required. Silicon rubberor polyurethane rubber can be used to fill the void above the flexiblediaphragm to serve as a pressure-coupling medium between the chemicalcomposition and the measuring diaphragm. The capacitance measured is inthe picofarad (pf) region, and the communicator can be pre-programmed toconvert the picofarad (pf) measurements to pounds per square inch.

In the illustrated embodiment, the real time temperature sensor is aband gap reference diode which is part of the integrated circuit. Analternative temperature sensor may comprise a bimetallic latchingsensor, for example a gold/chromium alloy (Au/Cr) on a silicon (Si)substrate.

Those skilled in the art will recognize that sensors and containers ofthe invention can take many different forms. For example, the containermay be a concrete pillar, as for a bridge or high rise building, and thesensor can take the form of a stain gauge, whereby stresses on thestructure of the pillar can be monitored. from the spirit of theinvention. The scope of the invention is limited only by the followingclaims.

What is claimed is:
 1. A method of monitoring physical parameters of acomposition (17) enclosed in a container (10,10 a, 10 b, 10 c)comprising the steps of a. embedding in a composition (17) a sensor(12,26,36) capable of measuring physical parameters of said compositionb. enclosing said composition (17) in a container (10, 10 a, 10 b, 10 c)c. winding an antenna (14,14 a, 16,16 a, 22,22 a, 24) around saidcontainer 910,10 a, 10 b, 10 c) in the proximity of said sensor(12,26,36) d. bringing a communication means into proximity with saidantenna (14,14 a, 16, 16 a, 22, 22 a ) and e. activating said sensor(12,26,36) through said antenna (14,14 a, 16,16 a, 22,22 a) (using saidcommunication means and receiving and recording a response from saidsensor (12,26,36) using said communication means.
 2. The method of claim1 comprising the further step of associating a ferrite core with saidantenna for amplifying signals to and from said sensor.
 3. The method ofclaim 1 comprising the further step of selecting said physicalparameters from the group comprising pressure data, chemical data,temperature data, moisture content data and mixtures thereof.
 4. Themethod of claim 1 comprising the further steps of enclosing said sensor(26) in a loop of wire (27), wherein said sensor (26) is electricallycoupled with said wire (27) to form a coupled sensor, placing a secondwire (22,22 a) adjacent to said coupled sensor, and placing an antenna(24) adjacent said second wire (22,22 a).
 5. The method of claim 1comprising the further steps of sandwiching said sensor (36) between anupper electrode (15) and a lower electrode (30).
 6. A method ofmonitoring physical parameters of a chemical composition (17) enclosedin a container (10) comprising the steps of (a) embedding in a chemicalcomposition (17) an electric field (E-field) sensor (36) capable ofmeasuring physical parameters of said chemical composition (17) (b)enclosing said composition in a container (10 b, 10 c) (c) placingE-field plates (44,46) at opposed sides of said container (10 b, 10 c)(d) creating an E-field in said plate (44,46) using an E-field driver(48) to induce a signal in and receive a signal from said sensor (36)(e) bringing an E-field reader into proximity to said plate (44,46), and(f) receiving and recording a response from said sensor (36).
 7. Acontainer (10,10 a, 10 b, 10 c) for containing a chemical composition(17), said container being made of impenetrable materials (18,18 a, 18b, 18 c) said impenetrable materials completely enclosing an interiorspace and having an inside and an outside, said container having anid-tag/sensor (12,26,36) disposed inside said container (10,10 a, 10 b,10 c), said id-tag/sensor being capable of retaining identificationinformation and measuring physical or chemical parameters of saidinterior space, and at least one antenna (14,14 a, 16,16 a, 22,22 a, 24)being associated with said id-tag/sensor, wherein said antenna comprisesat least two loops of wire (14,14 a, 16,16 a), a first said wire (16,16a) being disposed on said inside in the proximity of the impenetrablematerial (18) of said container (10) and said id-tag/sensor(12), and asecond said wire (14,14 a) being disposed on said outside around saidcontainer (10).
 8. The container of claim 7 wherein said first wire (16a) is inside said container (10).
 9. The container of claim 7 whereinsaid first wire (16) is outside said container (10).
 10. The containerof claim 7 wherein said first wire (16,16 a) is used as a receivingantenna and said second wire (14,14 a) is used as a transmitting antennafor said id-tag/sensor (12), and said id-tag/sensor (12) is activated bycommunication means associated with said transmitting antenna.
 11. Thecontainer of claim 7 wherein said sensor (26) is in proximity to andcoupled to a loop of wire (22) disposed in the proximity of saidimpenetrable material (18 a) of said container (10 a), and said loop ofwire (22) is inductively associated with an antenna (24) outside saidcontainer (10 a).
 12. The container of claim 11 wherein saidimpenetrable material (18 a) of said container (10 a) is a nonmetal. 13.The container of claim 7 wherein said id-tag/sensor (36) comprises achip sandwiched between an upper electrode (15) and a ground electrode(30) wherein said id-tag/sensor (36) is activated by at least twoelectric field (E-field) plates (44,46) at opposed sides of saidid-tag/sensor (36), wherein a first E-field plate comprises a metal core(54) in the interior of said container (10 c), and a second E-fieldplate comprises the impenetrable material (18 c) of said container (10c).